Exocrine pancreatic insufficiency and pancreatic fibrosis due to duodenal somatostatinoma in a patient with neurofibromatosis.

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).

A case of neurofibrosarcoma associated with neurofibromatosis--ganglioside analysis.

A patient with neurofibromatosis developed neurofibrosarcoma (NFS). The tumour was composed of spindle-shaped cells with atypical nuclei arranged in a fascicular or sheet-like fashion. The tumour cells had discontinuous basement membrane-like structures and were positively stained with the monoclonal antibody against S100 protein alpha chain. Both the primary tumour and its cultured cells contained GM3 and GD3 as major gangliosides. The ganglioside pattern of the primary tumour corresponds to that of NFS in our previous study. In the cultured NFS cells, the relative amount ratio of GM3 to GD3 is almost reversed compared to that of the primary tumour. This reversion may reflect some environmental influence on the ganglioside metabolism of NFS.

Immunohistochemical localization of type I, III, IV, V, and VI collagens and laminin in neurofibroma and neurofibrosarcoma.

By using antibodies to type I, III, IV, V, and VI collagens and laminin, we examined the localization of interstitial collagens and basement membrane components with indirect immunofluorescence and immunoelectron microscopy (IEM). Furthermore, the morphological changes of these collagens in malignant transformation were investigated. In neurofibroma, IEM showed type I, III, and V collagens to be present diffusely on cross-striated collagen fibrils, whereas type VI collagen was present between the fibrils. Type IV collagen and laminin were observed to surround tumor cells. In neurofibrosarcoma, tumor collagen bundles that reacted with antibodies to type I, III, V, and VI collagens were irregularly arranged. Immunofluorescent deposits that reacted with anti-type IV collagen and anti-laminin antibodies were decreased in number, showing a thin and sparse arrangement.

Neuropeptides in cutaneous neurofibromas of von Recklinghausen's disease.

The occurrence of neuropeptides was studied in neurofibromas of von Recklinghausen's disease by indirect immunofluorescence. All non-plexiform cutaneous neurofibromas contained abundant vasoactive intestinal polypeptide, peptide histidine-isoleucine and calcitonin gene-related peptide immunoreactive nerves. The nerves were small and unmyelinated. Neuropeptides might be responsible for itch that occurs especially in small cutaneous neurofibromas. Neuropeptides are also suggested to act as modulators and/or trophic factors for neurofibroma growth.

Glycosaminoglycans in neurofibromas.

Glycosaminoglycan (GAG) contents in neurofibromas (NFs) were examined to clarify how well they corresponded to their histological features. Eight cutaneous NFs and three plexiform NFs from five patients with Recklinghausen's (R) disease, two senile NFs and control dermis were subjected to the isolation of GAGs. The GAGs were then fractionated and quantitated with two-dimensional electrophoresis on cellulose acetate membranes. Dry weight/wet weight ratios of the NFs were lower than those of the controls; the plexiform NFs were the lowest. In these plexiform NFs, hyaluronic acid (HA) content was most increased and dermatan sulfate (DS) content most decreased, resulting in a marked decrease in the DS/HA ratio. Both cutaneous and senile NFs showed moderate decreases in DS content, increases in chondroitin sulfate and heparan sulfate contents, and slight increases in HA content, resulting in moderate decreases in the DS/HA ratio. Considering that cutaneous or senile NFs are relatively more fibrotic tumors than plexiform NFs, these differences in the GAGs between plexiform NFs and cutaneous or senile NFs appear to be consistent with the changes in GAGs previously described in physiological and pathological conditions such as fibrotic diseases. Thus these results suggest that studies of hereditary disorders like R disease might be useful for understanding the pathogenesis of so-called acquired diseases with unknown etiology.